/*
 * libid3tag - ID3 tag manipulation library
 * Copyright (C) 2000-2004 Underbit Technologies, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * $Id: genre.c,v 1.8 2004/01/23 09:41:32 rob Exp $
 */

# ifdef HAVE_CONFIG_H
#  include "config.h"
# endif

# include "global.h"

# include "id3tag.h"
# include "ucs4.h"

/* genres are stored in ucs4 format */
# include "genre.dat"

# define NGENRES    (sizeof(genre_table) / sizeof(genre_table[0]))

/*
 * NAME:    genre->index()
 * DESCRIPTION: return an ID3v1 genre string indexed by number
 */
id3_ucs4_t const *id3_genre_index(unsigned int index)
{
    return (index < NGENRES) ? genre_table[index] : 0;
}

/*
 * NAME:    genre->name()
 * DESCRIPTION: translate an ID3v2 genre number/keyword to its full name
 */
id3_ucs4_t const *id3_genre_name(id3_ucs4_t const *string)
{
    id3_ucs4_t const        *ptr;
    static id3_ucs4_t const genre_remix[] = { 'R', 'e', 'm', 'i', 'x', 0 };
    static id3_ucs4_t const genre_cover[] = { 'C', 'o', 'v', 'e', 'r', 0 };
    unsigned long           number;

    if (string == 0 || *string == 0)
        return id3_ucs4_empty;

    if (string[0] == 'R' && string[1] == 'X' && string[2] == 0)
        return genre_remix;
    if (string[0] == 'C' && string[1] == 'R' && string[2] == 0)
        return genre_cover;

    for (ptr = string; *ptr; ++ptr)
    {
        if (*ptr < '0' || *ptr > '9')
            return string;
    }

    number = id3_ucs4_getnumber(string);

    return (number < NGENRES) ? genre_table[number] : string;
}

/*
 * NAME:    translate()
 * DESCRIPTION: return a canonicalized character for testing genre equivalence
 */
static
id3_ucs4_t translate(id3_ucs4_t ch)
{
    if (ch)
    {
        if (ch >= 'A' && ch <= 'Z')
            ch += 'a' - 'A';

        if (ch < 'a' || ch > 'z')
            ch = ID3_UCS4_REPLACEMENTCHAR;
    }

    return ch;
}

/*
 * NAME:    compare()
 * DESCRIPTION: test two ucs4 genre strings for equivalence
 */
static
int compare(id3_ucs4_t const *str1, id3_ucs4_t const *str2)
{
    id3_ucs4_t c1, c2;

    if (str1 == str2)
        return 1;

    do
    {
        do
            c1 = translate(*str1++);
        while (c1 == ID3_UCS4_REPLACEMENTCHAR);

        do
            c2 = translate(*str2++);
        while (c2 == ID3_UCS4_REPLACEMENTCHAR);
    } while (c1 && c1 == c2);

    return c1 == c2;
}

/*
 * NAME:    genre->number()
 * DESCRIPTION: translate an ID3v2 genre name/number to its ID3v1 index number
 */
int id3_genre_number(id3_ucs4_t const *string)
{
    id3_ucs4_t const *ptr;
    int              i;

    if (string == 0 || *string == 0)
        return -1;

    for (ptr = string; *ptr; ++ptr)
    {
        if (*ptr < '0' || *ptr > '9')
            break;
    }

    if (*ptr == 0)
    {
        unsigned long number;

        number = id3_ucs4_getnumber(string);

        return (number <= 0xff) ? number : -1;
    }

    for (i = 0; i < NGENRES; ++i)
    {
        if (compare(string, genre_table[i]))
            return i;
    }

    /* no equivalent */

    return -1;
}
